Banjax wrote:Not totally happy with the risers but for my first time making them they will do.
You've got a great start to your collection

If you don't mind some advice on the risers, it looks like you're having trouble getting a nice, straight cut, is that right? I use a metal straight edge for shorter cuts and an aluminum T square for longer cuts, it looks like this one:
http://drywall101.com/images/content/fullsize/t-square.pngI use just a regular Exacto handle and number 11 blades, looks like this:

A single blade will get you through many cuts, you can tell when it starts getting dull as it will no longer cut cleanly but will start tearing the paper or foam core. That's when it's time to swap blades. Some people use box cutters but the thicker blade makes it tough to get a clean cut.
A "self-healing" cutting mat is an absolute must, they look like this:
https://www.thevillagehaberdashery.co.uk/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/o/l/olfa_cutting_mat.jpgIt will protect whatever surface you're cutting on, plus it keeps your piece from slipping while you're cutting. You can also use the lines on it as alignment assistance to make sure you're cutting straight. Plus because it is a soft surface you're cutting into your blades will stay sharper longer.
Anyway I first measure and make a couple of light marks with pencil and then I line up my straight edge on the marks. I'm left handed, so I apply downward pressure to the straight edge with my right hand and cut with my left. I do not try to cut all the way through on the first pass because there's a higher chance of the blade "walking" if you do that. Instead, apply medium pressure and cut from one end to the other in a smooth, continuous motion. Try to apply a slight amount of pressure into the straight edge to keep the cut from straying away from the straight edge. Make two or 3 more passes until you've cut all the way through to the other side.
It takes some practice but after a while you'll find you can make the cuts smooth every time and can also do it pretty quickly.
I hope that helps!